[PATCH 6/7] cgroup: use release_agent_path_lock in cgroup_release_agent_show()

From: Tejun Heo
Date: Fri May 09 2014 - 15:33:46 EST


release_path is now protected by release_agent_path_lock to allow
accessing it without grabbing cgroup_mutex; however,
cgroup_release_agent_show() was still grabbing cgroup_mutex. Let's
convert it to release_agent_path_lock so that we don't have to worry
about this one for the planned locking updates.

Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
---
kernel/cgroup.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index ff92bac..7b55ca5 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2373,11 +2373,10 @@ static int cgroup_release_agent_show(struct seq_file *seq, void *v)
{
struct cgroup *cgrp = seq_css(seq)->cgroup;

- if (!cgroup_lock_live_group(cgrp))
- return -ENODEV;
+ spin_lock(&release_agent_path_lock);
seq_puts(seq, cgrp->root->release_agent_path);
+ spin_unlock(&release_agent_path_lock);
seq_putc(seq, '\n');
- mutex_unlock(&cgroup_mutex);
return 0;
}

--
1.9.0

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